Method of extinguishing fires



Patented Jan. 5, 1932 UNITE STATES LODIAS J'. DUGAS, OF CHICAGO,ILLINOIS, ASSIGNOR '10 DU-GAS FIRE EXTINGUISHER 4 CORPORATION, OF NEWYORK, N. Y., A CORPORATION OF DELAWARE METHOD OF EXTINGUISHING- FIRESApplication led October 30, 1929. Serial No. 403,381.

This invention relates to a method of 'extinguishing fires and moreparticularly to a method wherein a gaseous mixture containing a dry fireextinguishing powder is employed for ghting fires.

It has heretofore been proposed to blow a fire extinguishing powder or asmoth'ering substance such as sand or the like onto fires for thepurpose of extinguishing them. Such proposed methods have not, however,come into practical use for various reasons. Chief among these reasonshave been the difficulty encountered in devising a fire extinguishingpowder that would not cake or hang up in the extinguisher container andalso the diiiiculty of obtaining a continuously uniform mixture of thechemical and gas. The tendency is for the dry re extinguishing powder tobe ejected in an irregular and uncontrolla- 'ble manner. Furthermore. ithas never heretofore been thought possible to fight really large fireswith a dry fire extinguishing powder, since no method nor means haspreviously been devised for efectively delivering the fire extinguishingpowder at any considerable distance from the point of discharge.Consequently, the only use to which dry chemicals have been put up tothe present time has been in fighting small tires, either by throwingthe dry chemical by hand from a small tube onto the iire or elsedirecting a feeble and irregular gaseous stream containing the chemicalagainst the fire.

It is therefore an object of this invention to provide an improvedmethod of extinguishing fires wherein a continuously uniform gaseousmixture containing a freely flowing tire extinguishing powder isdelivered Y at high pressure and at great velocity directly against theconflagration, the operator being protected from the heat of the fire bythe protective screen of gas and powder delivered against the fire.

It is a further important object of this invention to provide a methodof extinguishing very large fires, and especially oil fires, by thecombined effect of a non-fire supporting gas and a powdered chemicaladapted on being heated to form a fire smothering gas.

Other and further important objects of this invention will becomeapparent from the disclosures in the specification and the accompanyingdrawings.

This invention (in a preferred form) is illustrated in the drawings andhereinafter more fully described.

On the drawings:

Figure 1 illustrates the method of extinguishing fires according to myinvention.

Figure 2 is an elevational view of appara- 60 tus adapted for use withmy method.

Apparatus suitable for use with my method of extinguishing firescomprises a fire extinguisher container 1 and a gas cylinder 2 connectedthereto by piping 3, the container 1 and cylinder 2 being preferablymounted upon a wheeled truck, indicated as a whole by the referencenumeral 4'. It will be understood, however, that other designs and sizesof apparatus, either portable or stationary, may be employed. Fireextinguishers of a suitable type are more specifically described andclaimed in my copending application entitled Fire extinguishercontainer, Serial No. 325,675, filed December 13, 1928.

The cylinder 2 is preferably charged with nitrogen gas under about 1800lbs. per sq. ign-'pessilthough pressuresfrom 10() lbs. up to over 2000lbs. may beutilized satisfaetorily. Also other gases than nitrogen 80may be employed, such as carbon di'owxide.

The fire extinguishingclie'nicawmc'itained in receptacle 1 is a freelyiiowing powder adapted when heated to generate a ire smothering gas andanon-volatile residual flux that coats the burning object and preventsreignition thereof. A suitable type of fire extinguishing powder isdisclosed in the copending application of D. Julian Block, entitledComposition of matter, Serial No. 307.785, filed September 22, 1928. Thechemical therein disclosed consists principally of sodium bicarbonateand a substance adapted to render the bicarbonate non-packing andnon-hygroscopic, such as a metallic salt of a fatty acid, for instance,magnesium stearate. A fire extinguishing chemical of this type does notbecome wet when moisture is present nor does it pack or hang up in thecontainer but remains under all conditions in an apparently dry, freeflowing state.

The connecting piping 3 between the gas cylinder 2 and the extinguishercontainer 1 suitably includes a valve 5 and a second valve 6 forcontrolling the flow of gas into the container 1, pressure gages 7 and 8being positioned in said connecting piping 3 for indicating the pressureof the gas in the cylinder 2 and the pressure of the gas delivered intothe container 1. The gas mixes with and picks upthe dry chemicalcontained in the receptacle 1 and is delivered therefrom through aflexible hose 9 having at its end a valve controlled nozzle 10, throughwhich the gaseous mixture containing the uniformly distributed drychemical is discharged against the scene of confiagration. Preferably,the nozzle 10 is provided with a liaring, comparatively flat dischargeend 11 in order that the discharged stream of gas and chemical may bedistributed in a fan-shaped blast.

Figure 1 illustrates my method o-f extinguishing res, using the type ofapparatus and the type of chemical above described. The iire shown is anoil fire, a pit of oil being represented by the numeral 12. Flames andsmoke from the burning oil are represented by the reference numeral 13.In lighting a fire of this type, which, as is well known, is anextremely diiiicult one to extinguish by ordinary means, the operator,indicated by the reference numeral 14, drags the flexible hose 9 withhim to the burning pit and directs the nozzle 10 toward the base of thefire, the valves 5 and 6 being adjusted to deliver gas into thecontainer 1 under say about 200 lbs. per sq. in. pressure. A fan-shapedstream of gas under high pressure and at a. high velocity and containingthe dry lire extinguishing chemical uniformly mixed and distributedtherein, is thus delivered as at 15 directly against the base of the re.

The velocity and volume of the gaseous stream so delivered forms aprotective screen to prevent the operator from being scorched or burnedand permit him to approach the fire more closely than would otherwise bepossible. Also, the rapid iow of gas away from the operator draws withit a flow of cool air from behind the operator that surrounds him andfurther protects him from the heat of the iire.

The operator 14C starts at one end of the burning oil pit and proceedsrapidly toward the other end of the pit, usually being able toextinguish the re as rapidly as he can run. For instance, I havedemonstrated in putting out oil fires in pits as large as 6 x 36 ft.that the fire can be extinguished in less than ten seconds by my method.

It is an important feature of my method that the residues formed by thecomposition of the dry fire extinguishing chemical form over the burningobjects, such as the oil in the instance above described, a thick fluxthat prevents reignition or flare-back of the oil. This flux forms acontinuous protective coating over the surface of the oil and spreads asrapidly as the ame is eX- tinguished so that a Hare-back cannot occur.Because of the heat of the re and perhaps the inclusion of undecomposedchemicals in the residual flux, this flux foams up to form a relativelydeep smothering blanket over the heated surface of the oil.

It will be understood that other types of fires may be extinguished bymy method, including such extremely diiiicult fires to fight as burningether, alcohol, pyroxylin lacquer solvents, and the like. Ordinary woodres may likewise be extinguished in a similar manner.

The important feature of my invention is that the gaseous streamcontaining the dry chemical is delivered under such pressure and at sucha high velocity that it forms a protective screen for the operator,thereby enabling him to approach the re much more closely than wouldotherwise be possible. The very considerable advantages in fighting afire with a dry chemical rather than with a liquid are obvious, sincethere is no attendant damage such as results from the use of liquid.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I, therefore, do not purposelimiting the patent granted hereon otherwise than necessitated by theprior art.

I claim as my invention:

1. 'Ihe method of extinguishingiires which 5 comprises directingagainst'the iire a stream of a gas that doeslnetfsulpport combustion anda finely pqwde: hielnical capable of forming a lire sni'theringgas whenheated, the stream of"`gasiig`delivered in such a manner undersuchmghgpressure and at such high velocity as to formuaprotectivecurtain for the operatrwagainlst the heat of the fire, wherebytheop'erator can approach the lire much more closffelythanf: wouldotherwise be possible without himselbing burned.

2. The methodofextinguishing fires which comprises directing against thefire a fanshyapedlstream of mixed gas and dry tim tinguishing chemicalunder a discharge pressure of above 100 lbs. per sq. in., whereby thevelocity of said discharging stream is such as to drive the heat of there away from the operator and cause an inflow of unheated air around thebody of the operator to protect him and enable him to approach the firemore closely.

3. The method of extinguishing fires which comprises directing acontinuously uniform gaseous mixture containing a freely flowing fireextinguishing powder against a iire,

the gaseous mixture being delivered in a fanshape stream under such highpressure as to form a curtain to protect the operator against the heatof the re.

4. The method of extinguishing fires which comprises directing againstthe base of a re a fan-shaped, high pressure stream of a noncombustionsupporting gas containing a suspended powdered mixture composedprincipally of sodium bicarbonate, said mixture forming over the burningsurface a Ere smothering flux. t

In testimony whereof I have hereunto subscribed my name at Chicago, CookCounty,

Illinois.

LODIAS J. DUGAS.

